From patchwork Sun Nov 1 18:02:27 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [STABLE, V2] scmutil: abort if an empty revision is given to revpair() From: Matt Harbison X-Patchwork-Id: 11256 Message-Id: <7e21cf51738b1c2e1797.1446400947@Envy> To: mercurial-devel@selenic.com Cc: matt_harbison@yahoo.com Date: Sun, 01 Nov 2015 13:02:27 -0500 # HG changeset patch # User Matt Harbison # Date 1446342346 14400 # Sat Oct 31 21:45:46 2015 -0400 # Branch stable # Node ID 7e21cf51738b1c2e17975ad0adfff836ea973766 # Parent 6474b64045fb83733d6f7b774bbc8b2869bd1fed scmutil: abort if an empty revision is given to revpair() When using 'extdiff --patch' to check the changes in a rebase, 'precursors(x)' evaluated to an empty set because I forgot the --hidden flag, so the other revision was used as the replacement for the empty set. The result was the patch for the other revision was diffed against itself, and the tool saying there were no differences. That's misleading since the expected diff args were silently changed, so it's better to bail out. The other uses of scmutil.revpair() are commands.diff and commands.status, and it doesn't make sense to allow an empty revision there either. The code here was suggested by Yuya Nishihara. diff --git a/mercurial/scmutil.py b/mercurial/scmutil.py --- a/mercurial/scmutil.py +++ b/mercurial/scmutil.py @@ -717,6 +717,9 @@ if first is None: raise error.Abort(_('empty revision range')) + if (first == second and len(revs) >= 2 + and not all(revrange(repo, [r]) for r in revs)): + raise error.Abort(_('empty revision on one side of range')) # if top-level is range expression, the result must always be a pair if first == second and len(revs) == 1 and not _pairspec(revs[0]): diff --git a/tests/test-extdiff.t b/tests/test-extdiff.t --- a/tests/test-extdiff.t +++ b/tests/test-extdiff.t @@ -70,6 +70,12 @@ [1] #endif +Specifying an empty revision should abort. + + $ hg extdiff --patch --rev 'ancestor()' --rev 1 + abort: empty revision on one side of range + [255] + Test diff during merge: $ hg update -C 0